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3740 Poor ZFS send / receive performance due to snapshot hold / release processing
Submitted by: Steven Hartland <steven.hartland@multiplay.co.uk>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
*** 19,28 ****
--- 19,29 ----
* CDDL HEADER END
*/
/*
* Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 2013 by Delphix. All rights reserved.
+ * Copyright (c) 2013 Steven Hartland. All rights reserved.
*/
#include <sys/zfs_context.h>
#include <sys/dsl_userhold.h>
#include <sys/dsl_dataset.h>
*** 35,44 ****
--- 36,46 ----
#include <sys/zfs_ioctl.h>
#include <sys/zap.h>
typedef struct dsl_dataset_user_hold_arg {
nvlist_t *dduha_holds;
+ nvlist_t *dduha_chkholds;
nvlist_t *dduha_errlist;
minor_t dduha_minor;
} dsl_dataset_user_hold_arg_t;
/*
*** 51,135 ****
{
dsl_pool_t *dp = dmu_tx_pool(tx);
objset_t *mos = dp->dp_meta_objset;
int error = 0;
if (strlen(htag) > MAXNAMELEN)
! return (E2BIG);
/* Tempholds have a more restricted length */
if (temphold && strlen(htag) + MAX_TAG_PREFIX_LEN >= MAXNAMELEN)
! return (E2BIG);
/* tags must be unique (if ds already exists) */
! if (ds != NULL) {
! mutex_enter(&ds->ds_lock);
! if (ds->ds_phys->ds_userrefs_obj != 0) {
uint64_t value;
error = zap_lookup(mos, ds->ds_phys->ds_userrefs_obj,
htag, 8, 1, &value);
if (error == 0)
error = SET_ERROR(EEXIST);
else if (error == ENOENT)
error = 0;
}
- mutex_exit(&ds->ds_lock);
- }
return (error);
}
static int
dsl_dataset_user_hold_check(void *arg, dmu_tx_t *tx)
{
dsl_dataset_user_hold_arg_t *dduha = arg;
dsl_pool_t *dp = dmu_tx_pool(tx);
- nvpair_t *pair;
- int rv = 0;
if (spa_version(dp->dp_spa) < SPA_VERSION_USERREFS)
return (SET_ERROR(ENOTSUP));
! for (pair = nvlist_next_nvpair(dduha->dduha_holds, NULL); pair != NULL;
! pair = nvlist_next_nvpair(dduha->dduha_holds, pair)) {
! int error = 0;
dsl_dataset_t *ds;
! char *htag;
/* must be a snapshot */
! if (strchr(nvpair_name(pair), '@') == NULL)
error = SET_ERROR(EINVAL);
if (error == 0)
error = nvpair_value_string(pair, &htag);
! if (error == 0) {
! error = dsl_dataset_hold(dp,
! nvpair_name(pair), FTAG, &ds);
! }
if (error == 0) {
error = dsl_dataset_user_hold_check_one(ds, htag,
dduha->dduha_minor != 0, tx);
dsl_dataset_rele(ds, FTAG);
}
! if (error != 0) {
! rv = error;
! fnvlist_add_int32(dduha->dduha_errlist,
! nvpair_name(pair), error);
}
}
! return (rv);
}
! void
! dsl_dataset_user_hold_sync_one(dsl_dataset_t *ds, const char *htag,
! minor_t minor, uint64_t now, dmu_tx_t *tx)
{
dsl_pool_t *dp = ds->ds_dir->dd_pool;
objset_t *mos = dp->dp_meta_objset;
uint64_t zapobj;
! mutex_enter(&ds->ds_lock);
if (ds->ds_phys->ds_userrefs_obj == 0) {
/*
* This is the first user hold for this dataset. Create
* the userrefs zap object.
*/
--- 53,151 ----
{
dsl_pool_t *dp = dmu_tx_pool(tx);
objset_t *mos = dp->dp_meta_objset;
int error = 0;
+ ASSERT(dsl_pool_config_held(dp));
+
if (strlen(htag) > MAXNAMELEN)
! return (SET_ERROR(E2BIG));
/* Tempholds have a more restricted length */
if (temphold && strlen(htag) + MAX_TAG_PREFIX_LEN >= MAXNAMELEN)
! return (SET_ERROR(E2BIG));
/* tags must be unique (if ds already exists) */
! if (ds != NULL && ds->ds_phys->ds_userrefs_obj != 0) {
uint64_t value;
+
error = zap_lookup(mos, ds->ds_phys->ds_userrefs_obj,
htag, 8, 1, &value);
if (error == 0)
error = SET_ERROR(EEXIST);
else if (error == ENOENT)
error = 0;
}
return (error);
}
static int
dsl_dataset_user_hold_check(void *arg, dmu_tx_t *tx)
{
dsl_dataset_user_hold_arg_t *dduha = arg;
dsl_pool_t *dp = dmu_tx_pool(tx);
if (spa_version(dp->dp_spa) < SPA_VERSION_USERREFS)
return (SET_ERROR(ENOTSUP));
! if (!dmu_tx_is_syncing(tx))
! return (0);
!
! for (nvpair_t *pair = nvlist_next_nvpair(dduha->dduha_holds, NULL);
! pair != NULL; pair = nvlist_next_nvpair(dduha->dduha_holds, pair)) {
dsl_dataset_t *ds;
! int error = 0;
! char *htag, *name;
/* must be a snapshot */
! name = nvpair_name(pair);
! if (strchr(name, '@') == NULL)
error = SET_ERROR(EINVAL);
if (error == 0)
error = nvpair_value_string(pair, &htag);
!
! if (error == 0)
! error = dsl_dataset_hold(dp, name, FTAG, &ds);
!
if (error == 0) {
error = dsl_dataset_user_hold_check_one(ds, htag,
dduha->dduha_minor != 0, tx);
dsl_dataset_rele(ds, FTAG);
}
! if (error == 0) {
! fnvlist_add_string(dduha->dduha_chkholds, name, htag);
! } else {
! /*
! * We register ENOENT errors so they can be correctly
! * reported if needed, such as when all holds fail.
! */
! fnvlist_add_int32(dduha->dduha_errlist, name, error);
! if (error != ENOENT)
! return (error);
}
}
!
! /* Return ENOENT if no holds would be created. */
! if (nvlist_empty(dduha->dduha_chkholds))
! return (SET_ERROR(ENOENT));
!
! return (0);
}
!
! static void
! dsl_dataset_user_hold_sync_one_impl(nvlist_t *tmpholds, dsl_dataset_t *ds,
! const char *htag, minor_t minor, uint64_t now, dmu_tx_t *tx)
{
dsl_pool_t *dp = ds->ds_dir->dd_pool;
objset_t *mos = dp->dp_meta_objset;
uint64_t zapobj;
! ASSERT(RRW_WRITE_HELD(&dp->dp_config_rwlock));
!
if (ds->ds_phys->ds_userrefs_obj == 0) {
/*
* This is the first user hold for this dataset. Create
* the userrefs zap object.
*/
*** 138,504 ****
zap_create(mos, DMU_OT_USERREFS, DMU_OT_NONE, 0, tx);
} else {
zapobj = ds->ds_phys->ds_userrefs_obj;
}
ds->ds_userrefs++;
- mutex_exit(&ds->ds_lock);
VERIFY0(zap_add(mos, zapobj, htag, 8, 1, &now, tx));
if (minor != 0) {
VERIFY0(dsl_pool_user_hold(dp, ds->ds_object,
htag, now, tx));
! dsl_register_onexit_hold_cleanup(ds, htag, minor);
}
spa_history_log_internal_ds(ds, "hold", tx,
"tag=%s temp=%d refs=%llu",
htag, minor != 0, ds->ds_userrefs);
}
static void
dsl_dataset_user_hold_sync(void *arg, dmu_tx_t *tx)
{
dsl_dataset_user_hold_arg_t *dduha = arg;
dsl_pool_t *dp = dmu_tx_pool(tx);
! nvpair_t *pair;
uint64_t now = gethrestime_sec();
! for (pair = nvlist_next_nvpair(dduha->dduha_holds, NULL); pair != NULL;
! pair = nvlist_next_nvpair(dduha->dduha_holds, pair)) {
dsl_dataset_t *ds;
VERIFY0(dsl_dataset_hold(dp, nvpair_name(pair), FTAG, &ds));
! dsl_dataset_user_hold_sync_one(ds, fnvpair_value_string(pair),
! dduha->dduha_minor, now, tx);
dsl_dataset_rele(ds, FTAG);
}
}
/*
* holds is nvl of snapname -> holdname
* errlist will be filled in with snapname -> error
- * if cleanup_minor is not 0, the holds will be temporary, cleaned up
- * when the process exits.
*
! * if any fails, all will fail.
*/
int
dsl_dataset_user_hold(nvlist_t *holds, minor_t cleanup_minor, nvlist_t *errlist)
{
dsl_dataset_user_hold_arg_t dduha;
nvpair_t *pair;
pair = nvlist_next_nvpair(holds, NULL);
if (pair == NULL)
return (0);
dduha.dduha_holds = holds;
dduha.dduha_errlist = errlist;
dduha.dduha_minor = cleanup_minor;
! return (dsl_sync_task(nvpair_name(pair), dsl_dataset_user_hold_check,
! dsl_dataset_user_hold_sync, &dduha, fnvlist_num_pairs(holds)));
}
typedef struct dsl_dataset_user_release_arg {
nvlist_t *ddura_holds;
nvlist_t *ddura_todelete;
nvlist_t *ddura_errlist;
} dsl_dataset_user_release_arg_t;
static int
! dsl_dataset_user_release_check_one(dsl_dataset_t *ds,
! nvlist_t *holds, boolean_t *todelete)
{
! uint64_t zapobj;
! nvpair_t *pair;
! objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
! int error;
! int numholds = 0;
! *todelete = B_FALSE;
if (!dsl_dataset_is_snapshot(ds))
return (SET_ERROR(EINVAL));
zapobj = ds->ds_phys->ds_userrefs_obj;
! if (zapobj == 0)
! return (SET_ERROR(ESRCH));
! for (pair = nvlist_next_nvpair(holds, NULL); pair != NULL;
pair = nvlist_next_nvpair(holds, pair)) {
- /* Make sure the hold exists */
uint64_t tmp;
! error = zap_lookup(mos, zapobj, nvpair_name(pair), 8, 1, &tmp);
! if (error == ENOENT)
! error = SET_ERROR(ESRCH);
! if (error != 0)
return (error);
numholds++;
}
if (DS_IS_DEFER_DESTROY(ds) && ds->ds_phys->ds_num_children == 1 &&
ds->ds_userrefs == numholds) {
/* we need to destroy the snapshot as well */
!
! if (dsl_dataset_long_held(ds))
return (SET_ERROR(EBUSY));
- *todelete = B_TRUE;
}
return (0);
}
static int
dsl_dataset_user_release_check(void *arg, dmu_tx_t *tx)
{
! dsl_dataset_user_release_arg_t *ddura = arg;
! dsl_pool_t *dp = dmu_tx_pool(tx);
! nvpair_t *pair;
! int rv = 0;
if (!dmu_tx_is_syncing(tx))
return (0);
! for (pair = nvlist_next_nvpair(ddura->ddura_holds, NULL); pair != NULL;
! pair = nvlist_next_nvpair(ddura->ddura_holds, pair)) {
! const char *name = nvpair_name(pair);
int error;
dsl_dataset_t *ds;
nvlist_t *holds;
error = nvpair_value_nvlist(pair, &holds);
if (error != 0)
! return (SET_ERROR(EINVAL));
!
! error = dsl_dataset_hold(dp, name, FTAG, &ds);
if (error == 0) {
! boolean_t deleteme;
! error = dsl_dataset_user_release_check_one(ds,
! holds, &deleteme);
! if (error == 0 && deleteme) {
! fnvlist_add_boolean(ddura->ddura_todelete,
! name);
! }
dsl_dataset_rele(ds, FTAG);
}
if (error != 0) {
if (ddura->ddura_errlist != NULL) {
fnvlist_add_int32(ddura->ddura_errlist,
! name, error);
}
! rv = error;
}
}
! return (rv);
}
static void
dsl_dataset_user_release_sync_one(dsl_dataset_t *ds, nvlist_t *holds,
dmu_tx_t *tx)
{
dsl_pool_t *dp = ds->ds_dir->dd_pool;
objset_t *mos = dp->dp_meta_objset;
- uint64_t zapobj;
- int error;
- nvpair_t *pair;
! for (pair = nvlist_next_nvpair(holds, NULL); pair != NULL;
pair = nvlist_next_nvpair(holds, pair)) {
! ds->ds_userrefs--;
! error = dsl_pool_user_release(dp, ds->ds_object,
! nvpair_name(pair), tx);
VERIFY(error == 0 || error == ENOENT);
! zapobj = ds->ds_phys->ds_userrefs_obj;
! VERIFY0(zap_remove(mos, zapobj, nvpair_name(pair), tx));
spa_history_log_internal_ds(ds, "release", tx,
! "tag=%s refs=%lld", nvpair_name(pair),
! (longlong_t)ds->ds_userrefs);
}
}
static void
dsl_dataset_user_release_sync(void *arg, dmu_tx_t *tx)
{
dsl_dataset_user_release_arg_t *ddura = arg;
dsl_pool_t *dp = dmu_tx_pool(tx);
- nvpair_t *pair;
! for (pair = nvlist_next_nvpair(ddura->ddura_holds, NULL); pair != NULL;
! pair = nvlist_next_nvpair(ddura->ddura_holds, pair)) {
dsl_dataset_t *ds;
- VERIFY0(dsl_dataset_hold(dp, nvpair_name(pair), FTAG, &ds));
dsl_dataset_user_release_sync_one(ds,
fnvpair_value_nvlist(pair), tx);
! if (nvlist_exists(ddura->ddura_todelete,
! nvpair_name(pair))) {
ASSERT(ds->ds_userrefs == 0 &&
ds->ds_phys->ds_num_children == 1 &&
DS_IS_DEFER_DESTROY(ds));
dsl_destroy_snapshot_sync_impl(ds, B_FALSE, tx);
}
dsl_dataset_rele(ds, FTAG);
}
}
/*
* holds is nvl of snapname -> { holdname, ... }
* errlist will be filled in with snapname -> error
*
! * if any fails, all will fail.
*/
! int
! dsl_dataset_user_release(nvlist_t *holds, nvlist_t *errlist)
{
dsl_dataset_user_release_arg_t ddura;
nvpair_t *pair;
int error;
pair = nvlist_next_nvpair(holds, NULL);
if (pair == NULL)
return (0);
! ddura.ddura_holds = holds;
! ddura.ddura_errlist = errlist;
! ddura.ddura_todelete = fnvlist_alloc();
!
! error = dsl_sync_task(nvpair_name(pair), dsl_dataset_user_release_check,
! dsl_dataset_user_release_sync, &ddura, fnvlist_num_pairs(holds));
! fnvlist_free(ddura.ddura_todelete);
! return (error);
! }
!
! typedef struct dsl_dataset_user_release_tmp_arg {
! uint64_t ddurta_dsobj;
! nvlist_t *ddurta_holds;
! boolean_t ddurta_deleteme;
! } dsl_dataset_user_release_tmp_arg_t;
!
! static int
! dsl_dataset_user_release_tmp_check(void *arg, dmu_tx_t *tx)
! {
! dsl_dataset_user_release_tmp_arg_t *ddurta = arg;
! dsl_pool_t *dp = dmu_tx_pool(tx);
! dsl_dataset_t *ds;
! int error;
!
! if (!dmu_tx_is_syncing(tx))
! return (0);
!
! error = dsl_dataset_hold_obj(dp, ddurta->ddurta_dsobj, FTAG, &ds);
! if (error)
! return (error);
!
! error = dsl_dataset_user_release_check_one(ds,
! ddurta->ddurta_holds, &ddurta->ddurta_deleteme);
! dsl_dataset_rele(ds, FTAG);
! return (error);
! }
!
! static void
! dsl_dataset_user_release_tmp_sync(void *arg, dmu_tx_t *tx)
! {
! dsl_dataset_user_release_tmp_arg_t *ddurta = arg;
! dsl_pool_t *dp = dmu_tx_pool(tx);
! dsl_dataset_t *ds;
!
! VERIFY0(dsl_dataset_hold_obj(dp, ddurta->ddurta_dsobj, FTAG, &ds));
! dsl_dataset_user_release_sync_one(ds, ddurta->ddurta_holds, tx);
! if (ddurta->ddurta_deleteme) {
! ASSERT(ds->ds_userrefs == 0 &&
! ds->ds_phys->ds_num_children == 1 &&
! DS_IS_DEFER_DESTROY(ds));
! dsl_destroy_snapshot_sync_impl(ds, B_FALSE, tx);
! }
! dsl_dataset_rele(ds, FTAG);
! }
!
! /*
! * Called at spa_load time to release a stale temporary user hold.
! * Also called by the onexit code.
*/
! void
! dsl_dataset_user_release_tmp(dsl_pool_t *dp, uint64_t dsobj, const char *htag)
! {
! dsl_dataset_user_release_tmp_arg_t ddurta;
dsl_dataset_t *ds;
- int error;
! #ifdef _KERNEL
! /* Make sure it is not mounted. */
! dsl_pool_config_enter(dp, FTAG);
! error = dsl_dataset_hold_obj(dp, dsobj, FTAG, &ds);
if (error == 0) {
char name[MAXNAMELEN];
dsl_dataset_name(ds, name);
dsl_dataset_rele(ds, FTAG);
- dsl_pool_config_exit(dp, FTAG);
zfs_unmount_snap(name);
} else {
! dsl_pool_config_exit(dp, FTAG);
}
#endif
! ddurta.ddurta_dsobj = dsobj;
! ddurta.ddurta_holds = fnvlist_alloc();
! fnvlist_add_boolean(ddurta.ddurta_holds, htag);
!
! (void) dsl_sync_task(spa_name(dp->dp_spa),
! dsl_dataset_user_release_tmp_check,
! dsl_dataset_user_release_tmp_sync, &ddurta, 1);
! fnvlist_free(ddurta.ddurta_holds);
! }
!
! typedef struct zfs_hold_cleanup_arg {
! char zhca_spaname[MAXNAMELEN];
! uint64_t zhca_spa_load_guid;
! uint64_t zhca_dsobj;
! char zhca_htag[MAXNAMELEN];
! } zfs_hold_cleanup_arg_t;
! static void
! dsl_dataset_user_release_onexit(void *arg)
! {
! zfs_hold_cleanup_arg_t *ca = arg;
! spa_t *spa;
! int error;
! error = spa_open(ca->zhca_spaname, &spa, FTAG);
! if (error != 0) {
! zfs_dbgmsg("couldn't release hold on pool=%s ds=%llu tag=%s "
! "because pool is no longer loaded",
! ca->zhca_spaname, ca->zhca_dsobj, ca->zhca_htag);
! return;
! }
! if (spa_load_guid(spa) != ca->zhca_spa_load_guid) {
! zfs_dbgmsg("couldn't release hold on pool=%s ds=%llu tag=%s "
! "because pool is no longer loaded (guid doesn't match)",
! ca->zhca_spaname, ca->zhca_dsobj, ca->zhca_htag);
! spa_close(spa, FTAG);
! return;
! }
! dsl_dataset_user_release_tmp(spa_get_dsl(spa),
! ca->zhca_dsobj, ca->zhca_htag);
! kmem_free(ca, sizeof (zfs_hold_cleanup_arg_t));
! spa_close(spa, FTAG);
}
void
! dsl_register_onexit_hold_cleanup(dsl_dataset_t *ds, const char *htag,
! minor_t minor)
{
! zfs_hold_cleanup_arg_t *ca = kmem_alloc(sizeof (*ca), KM_SLEEP);
! spa_t *spa = dsl_dataset_get_spa(ds);
! (void) strlcpy(ca->zhca_spaname, spa_name(spa),
! sizeof (ca->zhca_spaname));
! ca->zhca_spa_load_guid = spa_load_guid(spa);
! ca->zhca_dsobj = ds->ds_object;
! (void) strlcpy(ca->zhca_htag, htag, sizeof (ca->zhca_htag));
! VERIFY0(zfs_onexit_add_cb(minor,
! dsl_dataset_user_release_onexit, ca, NULL));
}
int
dsl_dataset_get_holds(const char *dsname, nvlist_t *nvl)
{
--- 154,639 ----
zap_create(mos, DMU_OT_USERREFS, DMU_OT_NONE, 0, tx);
} else {
zapobj = ds->ds_phys->ds_userrefs_obj;
}
ds->ds_userrefs++;
VERIFY0(zap_add(mos, zapobj, htag, 8, 1, &now, tx));
if (minor != 0) {
+ char name[MAXNAMELEN];
+ nvlist_t *tags;
+
VERIFY0(dsl_pool_user_hold(dp, ds->ds_object,
htag, now, tx));
! (void) snprintf(name, sizeof (name), "%llx",
! (u_longlong_t)ds->ds_object);
!
! if (nvlist_lookup_nvlist(tmpholds, name, &tags) != 0) {
! tags = fnvlist_alloc();
! fnvlist_add_boolean(tags, htag);
! fnvlist_add_nvlist(tmpholds, name, tags);
! fnvlist_free(tags);
! } else {
! fnvlist_add_boolean(tags, htag);
! }
}
spa_history_log_internal_ds(ds, "hold", tx,
"tag=%s temp=%d refs=%llu",
htag, minor != 0, ds->ds_userrefs);
}
+ typedef struct zfs_hold_cleanup_arg {
+ char zhca_spaname[MAXNAMELEN];
+ uint64_t zhca_spa_load_guid;
+ nvlist_t *zhca_holds;
+ } zfs_hold_cleanup_arg_t;
+
+ static void
+ dsl_dataset_user_release_onexit(void *arg)
+ {
+ zfs_hold_cleanup_arg_t *ca = arg;
+ spa_t *spa;
+ int error;
+
+ error = spa_open(ca->zhca_spaname, &spa, FTAG);
+ if (error != 0) {
+ zfs_dbgmsg("couldn't release holds on pool=%s "
+ "because pool is no longer loaded",
+ ca->zhca_spaname);
+ return;
+ }
+ if (spa_load_guid(spa) != ca->zhca_spa_load_guid) {
+ zfs_dbgmsg("couldn't release holds on pool=%s "
+ "because pool is no longer loaded (guid doesn't match)",
+ ca->zhca_spaname);
+ spa_close(spa, FTAG);
+ return;
+ }
+
+ (void) dsl_dataset_user_release_tmp(spa_get_dsl(spa), ca->zhca_holds);
+ fnvlist_free(ca->zhca_holds);
+ kmem_free(ca, sizeof (zfs_hold_cleanup_arg_t));
+ spa_close(spa, FTAG);
+ }
+
+ static void
+ dsl_onexit_hold_cleanup(spa_t *spa, nvlist_t *holds, minor_t minor)
+ {
+ zfs_hold_cleanup_arg_t *ca;
+
+ if (minor == 0 || nvlist_empty(holds)) {
+ fnvlist_free(holds);
+ return;
+ }
+
+ ASSERT(spa != NULL);
+ ca = kmem_alloc(sizeof (*ca), KM_SLEEP);
+
+ (void) strlcpy(ca->zhca_spaname, spa_name(spa),
+ sizeof (ca->zhca_spaname));
+ ca->zhca_spa_load_guid = spa_load_guid(spa);
+ ca->zhca_holds = holds;
+ VERIFY0(zfs_onexit_add_cb(minor,
+ dsl_dataset_user_release_onexit, ca, NULL));
+ }
+
+ void
+ dsl_dataset_user_hold_sync_one(dsl_dataset_t *ds, const char *htag,
+ minor_t minor, uint64_t now, dmu_tx_t *tx)
+ {
+ nvlist_t *tmpholds;
+
+ if (minor != 0)
+ tmpholds = fnvlist_alloc();
+ else
+ tmpholds = NULL;
+ dsl_dataset_user_hold_sync_one_impl(tmpholds, ds, htag, minor, now, tx);
+ dsl_onexit_hold_cleanup(dsl_dataset_get_spa(ds), tmpholds, minor);
+ }
+
static void
dsl_dataset_user_hold_sync(void *arg, dmu_tx_t *tx)
{
dsl_dataset_user_hold_arg_t *dduha = arg;
dsl_pool_t *dp = dmu_tx_pool(tx);
! nvlist_t *tmpholds;
uint64_t now = gethrestime_sec();
! if (dduha->dduha_minor != 0)
! tmpholds = fnvlist_alloc();
! else
! tmpholds = NULL;
! for (nvpair_t *pair = nvlist_next_nvpair(dduha->dduha_chkholds, NULL);
! pair != NULL;
! pair = nvlist_next_nvpair(dduha->dduha_chkholds, pair)) {
dsl_dataset_t *ds;
+
VERIFY0(dsl_dataset_hold(dp, nvpair_name(pair), FTAG, &ds));
! dsl_dataset_user_hold_sync_one_impl(tmpholds, ds,
! fnvpair_value_string(pair), dduha->dduha_minor, now, tx);
dsl_dataset_rele(ds, FTAG);
}
+ dsl_onexit_hold_cleanup(dp->dp_spa, tmpholds, dduha->dduha_minor);
}
/*
+ * The full semantics of this function are described in the comment above
+ * lzc_hold().
+ *
+ * To summarize:
* holds is nvl of snapname -> holdname
* errlist will be filled in with snapname -> error
*
! * The snaphosts must all be in the same pool.
! *
! * Holds for snapshots that don't exist will be skipped.
! *
! * If none of the snapshots for requested holds exist then ENOENT will be
! * returned.
! *
! * If cleanup_minor is not 0, the holds will be temporary, which will be cleaned
! * up when the process exits.
! *
! * On success all the holds, for snapshots that existed, will be created and 0
! * will be returned.
! *
! * On failure no holds will be created, the errlist will be filled in,
! * and an errno will returned.
! *
! * In all cases the errlist will contain entries for holds where the snapshot
! * didn't exist.
*/
int
dsl_dataset_user_hold(nvlist_t *holds, minor_t cleanup_minor, nvlist_t *errlist)
{
dsl_dataset_user_hold_arg_t dduha;
nvpair_t *pair;
+ int ret;
pair = nvlist_next_nvpair(holds, NULL);
if (pair == NULL)
return (0);
dduha.dduha_holds = holds;
+ dduha.dduha_chkholds = fnvlist_alloc();
dduha.dduha_errlist = errlist;
dduha.dduha_minor = cleanup_minor;
! ret = dsl_sync_task(nvpair_name(pair), dsl_dataset_user_hold_check,
! dsl_dataset_user_hold_sync, &dduha, fnvlist_num_pairs(holds));
! fnvlist_free(dduha.dduha_chkholds);
!
! return (ret);
}
+ typedef int (dsl_holdfunc_t)(dsl_pool_t *dp, const char *name, void *tag,
+ dsl_dataset_t **dsp);
+
typedef struct dsl_dataset_user_release_arg {
+ dsl_holdfunc_t *ddura_holdfunc;
nvlist_t *ddura_holds;
nvlist_t *ddura_todelete;
nvlist_t *ddura_errlist;
+ nvlist_t *ddura_chkholds;
} dsl_dataset_user_release_arg_t;
+ /* Place a dataset hold on the snapshot identified by passed dsobj string */
static int
! dsl_dataset_hold_obj_string(dsl_pool_t *dp, const char *dsobj, void *tag,
! dsl_dataset_t **dsp)
{
! return (dsl_dataset_hold_obj(dp, strtonum(dsobj, NULL), tag, dsp));
! }
! static int
! dsl_dataset_user_release_check_one(dsl_dataset_user_release_arg_t *ddura,
! dsl_dataset_t *ds, nvlist_t *holds, const char *snapname)
! {
! uint64_t zapobj;
! nvlist_t *holds_found;
! objset_t *mos;
! int numholds;
if (!dsl_dataset_is_snapshot(ds))
return (SET_ERROR(EINVAL));
+ if (nvlist_empty(holds))
+ return (0);
+
+ numholds = 0;
+ mos = ds->ds_dir->dd_pool->dp_meta_objset;
zapobj = ds->ds_phys->ds_userrefs_obj;
! holds_found = fnvlist_alloc();
! for (nvpair_t *pair = nvlist_next_nvpair(holds, NULL); pair != NULL;
pair = nvlist_next_nvpair(holds, pair)) {
uint64_t tmp;
! int error;
! const char *holdname = nvpair_name(pair);
!
! if (zapobj != 0)
! error = zap_lookup(mos, zapobj, holdname, 8, 1, &tmp);
! else
! error = SET_ERROR(ENOENT);
!
! /*
! * Non-existent holds are put on the errlist, but don't
! * cause an overall failure.
! */
! if (error == ENOENT) {
! if (ddura->ddura_errlist != NULL) {
! char *errtag = kmem_asprintf("%s#%s",
! snapname, holdname);
! fnvlist_add_int32(ddura->ddura_errlist, errtag,
! ENOENT);
! strfree(errtag);
! }
! continue;
! }
!
! if (error != 0) {
! fnvlist_free(holds_found);
return (error);
+ }
+
+ fnvlist_add_boolean(holds_found, holdname);
numholds++;
}
if (DS_IS_DEFER_DESTROY(ds) && ds->ds_phys->ds_num_children == 1 &&
ds->ds_userrefs == numholds) {
/* we need to destroy the snapshot as well */
! if (dsl_dataset_long_held(ds)) {
! fnvlist_free(holds_found);
return (SET_ERROR(EBUSY));
}
+ fnvlist_add_boolean(ddura->ddura_todelete, snapname);
+ }
+
+ if (numholds != 0) {
+ fnvlist_add_nvlist(ddura->ddura_chkholds, snapname,
+ holds_found);
+ }
+ fnvlist_free(holds_found);
+
return (0);
}
static int
dsl_dataset_user_release_check(void *arg, dmu_tx_t *tx)
{
! dsl_dataset_user_release_arg_t *ddura;
! dsl_holdfunc_t *holdfunc;
! dsl_pool_t *dp;
if (!dmu_tx_is_syncing(tx))
return (0);
! dp = dmu_tx_pool(tx);
!
! ASSERT(RRW_WRITE_HELD(&dp->dp_config_rwlock));
!
! ddura = arg;
! holdfunc = ddura->ddura_holdfunc;
!
! for (nvpair_t *pair = nvlist_next_nvpair(ddura->ddura_holds, NULL);
! pair != NULL; pair = nvlist_next_nvpair(ddura->ddura_holds, pair)) {
int error;
dsl_dataset_t *ds;
nvlist_t *holds;
+ const char *snapname = nvpair_name(pair);
error = nvpair_value_nvlist(pair, &holds);
if (error != 0)
! error = (SET_ERROR(EINVAL));
! else
! error = holdfunc(dp, snapname, FTAG, &ds);
if (error == 0) {
! error = dsl_dataset_user_release_check_one(ddura, ds,
! holds, snapname);
dsl_dataset_rele(ds, FTAG);
}
if (error != 0) {
if (ddura->ddura_errlist != NULL) {
fnvlist_add_int32(ddura->ddura_errlist,
! snapname, error);
}
! /*
! * Non-existent snapshots are put on the errlist,
! * but don't cause an overall failure.
! */
! if (error != ENOENT)
! return (error);
}
}
!
! /* Return ENOENT if none of the holds existed. */
! if (nvlist_empty(ddura->ddura_chkholds))
! return (SET_ERROR(ENOENT));
!
! return (0);
}
static void
dsl_dataset_user_release_sync_one(dsl_dataset_t *ds, nvlist_t *holds,
dmu_tx_t *tx)
{
dsl_pool_t *dp = ds->ds_dir->dd_pool;
objset_t *mos = dp->dp_meta_objset;
! for (nvpair_t *pair = nvlist_next_nvpair(holds, NULL); pair != NULL;
pair = nvlist_next_nvpair(holds, pair)) {
! int error;
! const char *holdname = nvpair_name(pair);
!
! /* Remove temporary hold if one exists. */
! error = dsl_pool_user_release(dp, ds->ds_object, holdname, tx);
VERIFY(error == 0 || error == ENOENT);
!
! VERIFY0(zap_remove(mos, ds->ds_phys->ds_userrefs_obj, holdname,
! tx));
! ds->ds_userrefs--;
spa_history_log_internal_ds(ds, "release", tx,
! "tag=%s refs=%lld", holdname, (longlong_t)ds->ds_userrefs);
}
}
static void
dsl_dataset_user_release_sync(void *arg, dmu_tx_t *tx)
{
dsl_dataset_user_release_arg_t *ddura = arg;
+ dsl_holdfunc_t *holdfunc = ddura->ddura_holdfunc;
dsl_pool_t *dp = dmu_tx_pool(tx);
! ASSERT(RRW_WRITE_HELD(&dp->dp_config_rwlock));
!
! for (nvpair_t *pair = nvlist_next_nvpair(ddura->ddura_chkholds, NULL);
! pair != NULL; pair = nvlist_next_nvpair(ddura->ddura_chkholds,
! pair)) {
dsl_dataset_t *ds;
+ const char *name = nvpair_name(pair);
+
+ VERIFY0(holdfunc(dp, name, FTAG, &ds));
dsl_dataset_user_release_sync_one(ds,
fnvpair_value_nvlist(pair), tx);
! if (nvlist_exists(ddura->ddura_todelete, name)) {
ASSERT(ds->ds_userrefs == 0 &&
ds->ds_phys->ds_num_children == 1 &&
DS_IS_DEFER_DESTROY(ds));
dsl_destroy_snapshot_sync_impl(ds, B_FALSE, tx);
}
dsl_dataset_rele(ds, FTAG);
}
}
/*
+ * The full semantics of this function are described in the comment above
+ * lzc_release().
+ *
+ * To summarize:
+ * Releases holds specified in the nvl holds.
+ *
* holds is nvl of snapname -> { holdname, ... }
* errlist will be filled in with snapname -> error
*
! * If tmpdp is not NULL the names for holds should be the dsobj's of snapshots,
! * otherwise they should be the names of shapshots.
! *
! * As a release may cause snapshots to be destroyed this trys to ensure they
! * aren't mounted.
! *
! * The release of non-existent holds are skipped.
! *
! * At least one hold must have been released for the this function to succeed
! * and return 0.
*/
! static int
! dsl_dataset_user_release_impl(nvlist_t *holds, nvlist_t *errlist,
! dsl_pool_t *tmpdp)
{
dsl_dataset_user_release_arg_t ddura;
nvpair_t *pair;
+ char *pool;
int error;
pair = nvlist_next_nvpair(holds, NULL);
if (pair == NULL)
return (0);
! /*
! * The release may cause snapshots to be destroyed; make sure they
! * are not mounted.
*/
! if (tmpdp != NULL) {
! /* Temporary holds are specified by dsobj string. */
! ddura.ddura_holdfunc = dsl_dataset_hold_obj_string;
! pool = spa_name(tmpdp->dp_spa);
! #ifdef _KERNEL
! dsl_pool_config_enter(tmpdp, FTAG);
! for (pair = nvlist_next_nvpair(holds, NULL); pair != NULL;
! pair = nvlist_next_nvpair(holds, pair)) {
dsl_dataset_t *ds;
! error = dsl_dataset_hold_obj_string(tmpdp,
! nvpair_name(pair), FTAG, &ds);
if (error == 0) {
char name[MAXNAMELEN];
dsl_dataset_name(ds, name);
dsl_dataset_rele(ds, FTAG);
zfs_unmount_snap(name);
+ }
+ }
+ dsl_pool_config_exit(tmpdp, FTAG);
+ #endif
} else {
! /* Non-temporary holds are specified by name. */
! ddura.ddura_holdfunc = dsl_dataset_hold;
! pool = nvpair_name(pair);
! #ifdef _KERNEL
! for (pair = nvlist_next_nvpair(holds, NULL); pair != NULL;
! pair = nvlist_next_nvpair(holds, pair)) {
! zfs_unmount_snap(nvpair_name(pair));
}
#endif
+ }
! ddura.ddura_holds = holds;
! ddura.ddura_errlist = errlist;
! ddura.ddura_todelete = fnvlist_alloc();
! ddura.ddura_chkholds = fnvlist_alloc();
! error = dsl_sync_task(pool, dsl_dataset_user_release_check,
! dsl_dataset_user_release_sync, &ddura,
! fnvlist_num_pairs(holds));
! fnvlist_free(ddura.ddura_todelete);
! fnvlist_free(ddura.ddura_chkholds);
! return (error);
! }
! /*
! * holds is nvl of snapname -> { holdname, ... }
! * errlist will be filled in with snapname -> error
! */
! int
! dsl_dataset_user_release(nvlist_t *holds, nvlist_t *errlist)
! {
! return (dsl_dataset_user_release_impl(holds, errlist, NULL));
}
+ /*
+ * holds is nvl of snapdsobj -> { holdname, ... }
+ */
void
! dsl_dataset_user_release_tmp(struct dsl_pool *dp, nvlist_t *holds)
{
! ASSERT(dp != NULL);
! (void) dsl_dataset_user_release_impl(holds, NULL, dp);
}
int
dsl_dataset_get_holds(const char *dsname, nvlist_t *nvl)
{